The Nagpur tahsil forms the central and south-western portion of the District, lying between 20 46 and 21 23 N. and. 78 44 and 79 19 E. It is bounded on the north by the river Koilar as far as its junction with the Kanhan above Kamptee, and thence by the Kanhan itself, separation it from Ramtek. South and east lies Umrer the Wunna river marking the border for about 15 miles, while to the south-west the tahsil adjoins the Wardha District, and to the wet and north-west Katol. The tahsil may be divided into four marked geographical tracts, the Kalmeshwar plain, the Kauras plateau, the Wunna vally, and the Nagpur-Kamptee plain. The first of these tracts, the Kalmeshwar plain, lies in the northern portion of the tahsil. It is drained by the Koilar, and its principal tributary the Chandrabhaga. The second tract, which differs considerably in its natural features from every other part of the tahsil, is the plateau of Kauras, a continuation of the uplands of Katol, which round off in this tahsil and form an extensive and fairly well cultivated tract of high land. The Wunna valley, the third tract, comprises the central and southern portions of the tahsil, traversed by the Great Indian Peninsula Railway. The surface is generally undulation, and is broken by a few low hills. The fourth tract comprises the whole of the Nagpur pargana, the level plain ling to the south and east of Nagpur, drained by the Nag river and its tributaries. The first and fourth of these areas are the most fertile and contain the best wheat cultivation; in the third there is also wheat but to a far less extent, and there is abundance of juar and a fair amount of cotton. The second tract has very little wheat indeed and the poor lands are chiefly cultivated with juar, turn and cotton.